By Hara Estroff Marano,

Doctors can predict the onset of eating disorders and one expert says two-thirds of people with eating disorders experience some form of clinical anxiety.

The mental disorder with the highest mortality rate isn’t depression. Nor is it schizophrenia. It’s eating disorders. Up to 20 percent of those with eating disorders succumb to their illness. So it would be an important medical milestone if there were some way to predict who is likely to develop an eating disorder—and possibly head it off.

More than 90 percent of those who develop bulimia or anorexia, or some combination of the two, are young women in their teens and 20s, and most develop the disorder in adolescence. American colleges report that all three disorders are rampant on campus, afflicting up to 40 percent of students in either florid or subclinical form at some point during the student years.

At any one time, about 2 to 3 percent of adolescents have bulimia, and 0.5 to 1 percent of adolescents have anorexia. According to child psychiatrists, 13 percent of high school girls purge.

Eating disorders have doubled in incidence since the 1960s, and increasingly they are striking in younger age groups. They also increasingly occur in diverse ethnic and sociocultural groups.

In a significant advance, a team of researchers reports it has identified a major vulnerability factor for eating disorders that may give doctors a way to get an early start on prevention and treatment. It’s childhood anxiety.

According to psychiatrist Walter H. Kaye at the University of Pittsburgh, most people—two thirds, in fact—with eating disorders experienced some sort of clinical anxiety, such as obsessive-compulsive disorder or social phobia, at some point in their lives. A significant number of them—42 percent—developed the anxiety disorder when they were children, years before the eating disorder.

“We identified a strong link between anxiety disorders and eating disorders that shows they not only share many of the same personality traits, but they also likely share a genetic pathway,” Dr Kaye reports on the basis of study of 672 individuals. “This study shows that to help young women recover from these devastating illnesses, doctors need to develop strategies to treat both the eating disorder and the underlying anxiety. It is also possible that treating the anxiety disorder early on may provide some preventive effect against eating disorders.”

Kaye and his colleagues found that among the patients they examined, the anxiety persisted even after women had recovered from an eating disorder. The normal rate of anxiety in healthy women is 13 to 30 percent, compared with 66 percent among the eating-disordered. Even those who did not have a diagnosable anxiety disorder had identifiable anxiety traits, such as harm avoidance, generalized anxiety and perfectionism.

Rates of anxiety conditions were similar for all three subtypes of eating disorders—anorexia, bulimia and combined anorexia and bulimia. Two anxiety disorders were especially associated with later eating disorders—obsessive-compulsive disorder in 41 percent and social phobia in 20 percent.

The frequency of obsessive-compulsive disorder in the background of those with eating disorders was especially striking, because OCD normally afflicts only 2 to 3 percent of children. Because the normal age of onset of OCD is the 20s, Kaye and his colleagues believe that childhood OCD could be a significant predictor of a future eating disorder.

Anxiety in children is nothing to take sneeze at. Experts have recognized it as a risk factor for later depression. And now it may be the precursor to eating disorders. The good news is it is modifiable with cognitive-behavior therapy.